How did Crimea vote 97% in favor of rejoining Russia

I think you are mistaken. My understanding is that the OSCE were invited, but they refused to attend because the invitation came from the local Crimean government, not the national Ukrainian government, and only the latter has the authority to issue such invitations. At least, this is what Reuters is reporting: Crimea invites OSCE observers for referendum on joining Russia

97% is still very suspiciously high. There are no hints of secession in Ohio but I don’t know if you’d even get 97% of them voting to remain in the US if polled?

Nope. There is nothing “complicated” about a plebisite held under the guns of an invading power, organized in two weeks, without any credible neutral oversight (and with the press suppressed), voting overwhelmingly in favour of that invasion, being wholly without legitimacy. Never mind the fact that the plebicite in issue did not even have an option for maintaining the status quo.

Noting that the plebicite is wholly without legitimacy does not require any analysis of the alleged shortcomings of the current Kiev government; the fact that ‘most people expected’ support for joining Russia is equally irrelevant (in fact, allegedly a previous poll had approval for annexation running at 40%).

Cite: http://fivethirtyeight.com/features/many-signs-pointed-to-crimea-independence-vote-but-polls-didnt/

So we have gone from 40% in a poll a month ago, to 97% in the plebicite.

Russia’s propaganda move here has been astonishingly inept. If indeed a strong majority in Crimea favoured Russian annexation, Russia ought to have been bending over backwards to make the plebisite as fair as possible - such approval would have gone a long way towards undermining Western opposition. As it is, the rational response to such a rigged plebicite is to find that it lacks any credibility.

OSCE says they were prevented from entering Crimea by armed men.

Did you read anything beyond the headline? The first paragraph makes it clear that the observers who were denied entry were “OSCE military observers”, not election observers as we were discussing here. The last paragraph of your article says that the OSCE deliberately chose not to send any “election monitors” even though the Crimean and Russian governments wanted them.

When there’s demonstrable evidence 123% of the population voted in at least one (critical) example it’s not really an “assumption” any more, is it ?